Tuesday, 12 May 2020

How metal surfaces work as instant bacteria killers

Bacterial
pathogens can live on surfaces for days. What if frequently touched surfaces
such as doorknobs could instantly kill them off?

Purdue
University engineers have created a laser treatment method that could
potentially turn any metal surface into a rapid bacteria killer -- just by
giving the metal's surface a different texture.

In a
study published in the journal Advanced Materials Interfaces, the researchers
demonstrated that this technique allows the surface of copper to immediately
kill off superbugs such as MRSA.

The
technique is not yet tailored to killing viruses such as the one responsible
for the COVID-19 pandemic, which are much smaller than bacteria.

Giving implants an
antimicrobial surface
would prevent the spread of infection and antibiotic resistance, Rahimi said,
because there wouldn't be a need for antibiotics to kill off bacteria from an
implant's surface.

The
technique might apply to metallic alloys that also are known to have antimicrobial
properties. Metals such as copper normally have a really smooth surface, which
makes it difficult for the metal to kill bacteria by contact.

The
laser-texturing has a dual effect: The technique not only improves direct
contact, but also makes a surface more hydrophilic. For orthopedic implants,
such a surface allows bone cells to more strongly attach, improving how well
the implant integrates with bone. Rahimi's team observed this effect with
fibroblast cells.

Due
to the simplicity and scalability of the technique, the researchers believe
that it could easily be translated into existing medical device manufacturing
processes.